Double cut folder with variable knife mounting locations on cutting cylinders

Abstract

A double cut folder is provided for a printing press. The folder has a first cutting cylinder pair including a first knife cylinder and a first anvil cylinder for perforating a web, and a second cutting cylinder pair including a second knife cylinder and a second anvil cylinder for cutting the web into signatures. Each cutting cylinder pair includes a plurality of knife mounting locations and a plurality of cutting rubber locations. Each knife mounting location is configured to hold a knife box. A first subset of the plurality of knife mounting locations each have a knife box secured therein, and a second subset of the plurality of knife mounting locations do not have a knife box secured therein.

What is claimed is: 
     
       1. A method of cutting a web into variable length signatures comprising the steps of:
 perforating a web with a first cutting cylinder pair and cutting the web into signatures having a first length with a second cutting cylinder pair, wherein each cutting cylinder pair includes a plurality of knife mounting locations and a plurality of cutting rubber locations, each knife mounting location configured to hold a knife box, wherein a first subset of the plurality of knife mounting locations each have a knife box secured therein, and a second subset of the plurality of knife mounting locations does not have a knife box or an anvil secured therein; 
 on the first cutting cylinder pair and on the second cutting cylinder pair, removing one or more of the knife boxes from the first subset of knife mounting locations and securing one or more knife boxes into respective ones of the second subset of knife mounting locations, and thereafter; 
 perforating a web with the first cutting cylinder pair and cutting the web into signatures having a second length with the second cutting cylinder pair; 
 wherein the first cylinder pair includes a first knife cylinder and a first anvil cylinder, and the second cylinder pair includes a second knife cylinder and a second anvil cylinder and the first and second knife cylinders have a same diameter as a blanket cylinder transferring an image to the web. 
 
     
     
       2. The method of  claim 1 ,
 wherein the plurality of knife mounting locations include twelve locations, and wherein, during said cutting the web into signatures of the first length, four of the twelve knife mounting locations hold respective knife boxes; 
 wherein the removing includes removing three of the four knife boxes; and 
 wherein the securing includes securing four or five knife boxes into respective ones of the second subset of knife mounting locations. 
 
     
     
       3. The method of  claim 1 ,
 wherein the plurality of knife mounting locations include twelve locations, and wherein, during said cutting the web into signatures of the first length, five of the twelve knife mounting locations hold respective knife boxes; 
 wherein the removing includes removing four of the five knife boxes; and 
 wherein the securing includes securing three or five knife boxes into respective ones of the second subset of knife mounting locations. 
 
     
     
       4. The method of  claim 1 ,
 wherein the plurality of knife mounting locations include twelve locations, and wherein, during said cutting the web into signatures of the first length, six of the twelve knife mounting locations hold respective knife boxes; 
 wherein the removing includes removing five of the six knife boxes; and 
 wherein the securing includes securing three or four knife boxes into respective ones of the second subset of knife mounting locations. 
 
     
     
       5. The method of  claim 1 , further comprising supporting the web and signatures using tapes, the tapes running between the second knife cylinder and the second anvil cylinder. 
     
     
       6. The method of  claim 1 , wherein all of the knife mounting locations of the first cutting cylinder pair are on the first knife cylinder, and all of the knife mounting locations of the second cutting cylinder pair are on the second knife cylinder. 
     
     
       7. The method of  claim 1 , wherein some of the knife mounting locations of the first cutting cylinder pair are on the first knife cylinder and some of the knife mounting locations of the first cutting cylinder pair are on the first anvil cylinder; and wherein some of the knife mounting locations of the second cutting cylinder pair are on the second knife cylinder and some of the knife mounting locations of the second cutting cylinder pair are on the second anvil cylinder.